کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6413949 1629985 2012 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Unsaturated zone characterization in soil through transient wetting and drying using GPR joint time-frequency analysis and grayscale images
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Unsaturated zone characterization in soil through transient wetting and drying using GPR joint time-frequency analysis and grayscale images
چکیده انگلیسی

SummaryThis paper describes an experimental method to characterize the soil's unsaturated zone by constructing a scenario in which transient downward water infiltration took place from the topsoil to the bottom soil continuously. During the water infiltration, GPR waveforms and side-view grayscale images of the soil column were simultaneously and continuously captured. The GPR wavelets associated with the wetting front were analyzed using short time fourier transform (STFT) algorithm. The downward wetting front and the stretch of unsaturated transition zone decelerated and eased the wetting front's reflection in the time domain; as well as reduced the peak frequency and attenuated the frequency spectra in the frequency domain. The subsequent drying process further attenuated but accelerated the wetting front's reflection in both time and frequency domains. These observations were correlated with the image pixel profiles, from which GPR velocity profiles at different lapsed times were generated after computation via a complex refractive index model (CRIM). The CRIM method is entirely non-invasive and not only offers very detailed measurement of the water saturation profile of the transition zone in laboratory scale, but also is potentially useful for the further study of a variety of vadose zone properties.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Hydrology - Volumes 452–453, 25 July 2012, Pages 1-13
نویسندگان
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